Mac OS X: You don't need to click through system settings or use a third-party app to hide and show the OS X dock, all you need is a quick keyboard shortcut. Just hit Command+Option+D at any time, and the dock will glide away (or back again).

You can also activate hiding with a couple of clicks, by right-clicking on the dock separator and selecting "Turn Hiding On." Magnification can be turned on or off from that same pop-up menu as well.